Method and apparatus for applying a knot to a suture

ABSTRACT

A knot placement device allows a physician to apply a knot for securing two or more suture ends extending from an incision in a vessel or organ of a patient relative to each other in order to seal an opening in the vessel or organ. The knot placement device has a handle and an elongate shaft and a push rod slidably inserted in said shaft. A knot is disposed in the distal end of the shaft. An actuator on the handle may be depressed to distally advance said push rod relative to said shaft and thereby distally advance said knot. The knot may include a knot body having an inner cavity and a plug sized to fit securely within the inner cavity. In use, the plug may be inserted into the inner cavity of the knot body to fixedly hold two or more suture ends between the knot body and the plug.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 11/455,894,filed on Jun. 19, 2006, which claims the benefit of U.S. ProvisionalApplication No. 60/693,582, filed on Jun. 20, 2005 and U.S. ProvisionalApplication No. 60/709,485, filed on Aug. 19, 2005, the entirety ofwhich are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Certain embodiments of the invention relate to suturing incisions and,more specifically, to the use of sutures for closing incisions invessels or in organs within a body.

2. Description of the Related Art

Surgeons frequently encounter the need to close incisions, wounds, orotherwise joining tissue portions with a suture. After passing thesuture through the tissue portions, the surgeon must tie and cinch thesuture to draw the tissue portions together and prevent them fromseparating. When sutures are tied in a region having restricted access,such as the end of a tissue tract leading to an artery, the surgeon ispresented with special challenges. Sutures can often he difficult tohandle, thereby increasing the time that it takes for a surgeon to tie asuture. Accordingly, what is needed is a faster and more effective wayto tie and cinch a suture.

SUMMARY OF THE INVENTION

Certain embodiments of the present invention describe various methodsand apparatus for applying a knot to a suture. When two ends of a sutureextend away from an incision in a vessel or an organ of a patient, thepreferred embodiments provide a method and apparatus for desirablysecuring two suture portions relative to each other, with the securementbeing provided adjacent the incision to hold the incision closed. Asused herein, the term “knot” is a broad term encompassing its ordinarymeaning and includes, but is not limited to, any arrangement, componentor combination of components designed to fixedly hold a suture relativeto a desired knot location. More preferably, a knot may encompass anyarrangement, component or combination of components designed to fixedlyhold two portions of a suture relative to a desired knot location. Thus,a knot encompasses arrangements in which suture portions are tied, andalso encompasses arrangements in which suture portions are securely heldrelative to one another without being tied. The desired knot locationmay include an incision, a wound, a body cavity, an opening in bodytissue, and two adjacent body tissues wherein the space between the twoadjacent body tissues is desired to be closed. The two suture portionsmay be portions of the same suture or different sutures.

In one embodiment, a knot placement device is provided. The knotplacement device preferably includes a handle and a shaft. The handlecomprises a proximal end and a distal end. The shaft comprises aproximal end and a distal end which extends distally from the handle. Aknot is disposed, either partially or entirely, within the distal end ofthe shaft. The handle further comprises an actuator which places theknot about two suture portions to fix the two suture portions relativeto one another.

In one embodiment, the actuator may be a thumb or finger button designedfor cooperation with a cam. The cam may be fixedly attached to a pushrod. The push rod is concentrically and slidably disposed within anouter tube. The outer tube may be fixedly attached to a distal endportion of the handle. The knot placement device may further comprise anintermediate tube concentrically and slidably disposed between the outertube and the push rod. The intermediate tube comprises a proximal endand a distal end. The proximal end of the intermediate tube may belocated between the cam and the distal end portion of the handle.Partial depression of the actuator distally advances the push rod. Atsome degree of depression, the actuator contacts the proximal end of theintermediate tube, thus distally advancing the intermediate tube.

In one embodiment, the intermediate tube may comprise a key. The outertube, the end portion, or both may include a keyway designed forcooperation with the key. The key and associated keyway maintainrotational alignment of the intermediate tube relative to the outertube. In another embodiment, the intermediate tube may comprise akeyway, and the outer tube or the end portion may comprise a key.

In one embodiment, the shaft comprises an outer tube having a proximalend and a distal end. The outer tube may comprise an aperture locatednear its distal end. The shaft may further comprise an intermediate tubeconcentrically and slidably disposed within the outer tube. Theintermediate tube may comprise a slot located at or near its distal end.A push rod may be concentrically and slidably disposed within theintermediate tube and outer tube. A knot is disposed, either partiallyor entirely, within the distal end of the outer tube.

In one embodiment, the knot comprises a plug and a knot body, whereinthe plug is adapted to be received within the knot body. The plugcomprises a proximal end and a distal end, and may be of a generallyconstant outer diameter. Alternatively, the plug may be generallytapered from the proximal end to the distal end. Alternatively, the plugmay comprise a portion of generally constant outer diameter and agenerally tapered portion. The plug may also comprise a rounded orchamfered edge at the distal end. The plug may also comprise a shoulderlocated near the proximal end having an increased outer diameter.

The knot body may be generally tubular and comprise a proximal end, adistal end, and a longitudinal axis. The knot body may be of a generallyconstant inner diameter and outer diameter. Alternatively, the innerdiameter, the outer diameter, or both may generally taper along thelongitudinal axis of the knot body. Alternatively, the inner diameter,the outer diameter, or both may generally taper along a portion of thelongitudinal axis and may be of a generally constant inner diameter,outer diameter or both over a portion of the longitudinal axis.

The knot body may comprise an opening at its distal end. The opening atthe distal end of the knot body may, in some embodiments, be of areduced diameter. The knot body may also comprise an opening at theproximal end. The opening at the proximal end may, in some embodiments,be of a reduced diameter. The knot body may further comprise protrusionsfrom the inner surface of the knot body toward the longitudinal axis.

In one embodiment, the knot body may be located distally from the plugwithin the outer tube. In another embodiment, the plug may be locateddistally from the knot body within the outer tube.

In one embodiment, a method is provided for placing a knot on a sutureto close an opening in the body. A pair of suture ends is passed througha threader. The threader is pulled through a passage in the distal endof a shaft of a knot placement device. As the threader is pulled throughthe passage, the suture portions are drawn through the passage, anddesirably positioned within a knot body positioned at a distal end ofthe shaft. Tension may be applied to the suture portions as the knotplacement device is slid along the suture portions toward a pair oftissue portions. The knot placement device is advanced until the knotbody or distal end of the device is in contact with a tissue portion. Anactuator is depressed, which in one embodiment advances a push rodwithin the shaft against a plug and advances the plug into the knotbody. This traps the suture between the plug and the knot body. In onepreferred embodiment, continued depression of the actuator causes anintermediate tube to be advanced to sever the suture portions, eject theknot from the placement device, or both. The device is then retractedfrom the patient.

In one embodiment, after the knot is ejected and before the suture endsare severed, the push rod is positioned substantially flush with adistal end of the shaft. The distal end of the shaft is used to push theknot toward the tissue portions to further secure the knot and draw thetissue portions closer together.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wound site having a pair of sutureends extending therefrom.

FIG. 2 is a side view of one embodiment of a knot placement device.

FIG. 3 is a side view of the shaft, cam, and distal end portion of theknot placement device of FIG. 2 with a knot shown within the shaft inphantom.

FIG. 4 is a partial cross-sectional side view of the handle of the knotplacement device of FIG. 2.

FIG. 5 is a partial cross-sectional side view of the distal end of theshaft of the knot placement device of FIG. 2.

FIG. 6 is a perspective view of the distal end of the outer tube of theknot placement device of FIG. 2.

FIG. 7 is a perspective view of the distal end of the intermediate tubeof the knot placement device of FIG. 2.

FIG. 8 is a side view of the outer tube of FIG. 6.

FIG. 9 a is a top view of the intermediate tube of FIG. 7.

FIG. 9 b is a side view of the intermediate tube of FIG. 7.

FIG. 10 is a perspective view of one embodiment of a knot.

FIG. 11 is a cross-sectional side view of another embodiment of a knot.

FIG. 12 is a cross-sectional side view of another embodiment of a knot.

FIG. 13 is a perspective view of another embodiment of a knot.

FIG. 14 is a transverse cross-sectional view of the knot of FIG. 13.

FIG. 15 is a cross-sectional side view of another embodiment of a knot.

FIG. 16 a is a cross-sectional side view of another embodiment of a knotand illustrating a routing of a suture through the knot body.

FIG. 16 b is a cross-sectional side view of the embodiment of the knotof FIG. 16 a and illustrating an alternative routing of a suture throughthe knot body.

FIG. 17 a is a perspective view of another embodiment of a knot.

FIG. 17 b is a cross-sectional side view of the embodiment of a knotshown in FIG. 17.

FIG. 18 a is a cross-sectional side view of another embodiment of aknot.

FIG. 18 b is a cross-sectional side view of the knot of FIG. 8 a.

FIG. 18 c is a cross-sectional side view of the knot of FIGS. 18 a-18 b.

FIG. 19 is a partial cross-sectional view of a knot placement device,with suture ends passing through a threader.

FIG. 20 illustrates the device of FIG. 19 having two suture portionspassing therethrough, with the distal end of the device in contact witha tissue portion.

FIG. 21 illustrates the device of FIGS. 19-20 with the push rod beingadvanced until the plug is inserted into the knot body, trapping thesuture portions between the plug and knot body.

FIG. 22 illustrates the device of FIGS. 19-21, the push rod beingfurther advanced, the intermediate tube also being advanced to eject theknot from the device and sever the suture portions.

FIG. 23 illustrates the knot of FIGS. 19-22, in its final placement.

FIGS. 24 and 25 illustrate another embodiment of a knot having anatraumatic tip.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention described belowrelate particularly to applying a knot to two portions of a suture. Moreparticularly, the preferred embodiments relate to applying a knot toportions of a suture extending from a treatment location of a patient.The treatment location may be any desired location, such as an arterialvessel, a venous vessel, or any other body tissue. Suture ends may bethe ends of the same suture or may be the ends of separate sutures.

FIG. 1 illustrates the wound site of a patient wherein it may be desiredto apply a knot to a suture. More particularly, FIG. 1 shows an incision30 in the patient's skin used to perform any sort of treatment on thepatient. After the patient has been treated, a suture 34 is introducedinto the patient through a catheter sheath introducer (CSI) 44 for thepurpose of drawing together tissue portions 36 and 38 (shown in phantomin FIG. 1). Two end portions 40 and 42 of the suture 34 extend from thetissue portions 36, 38, respectively, which may, for example, be theresult of a wound or an internal incision in a blood vessel or an organ.The suture 34 may be introduced into the patient by any suitable manner,including those described in U.S. Pat. No. 5,860,990, U.S. Pat. No.6,117,144, U.S. Pat. No. 6,562,052, and Applicant's co-pendingapplication Ser. No. 11/235,751 filed Sep. 27, 2005, now U.S.Publication No. 2006-0069397, all of which are hereby incorporated byreference in their entirety. Suture 34 may be, but is not limited to,0.007″ diameter biodegradable material or non-biodegradable materials,such as polypropylene. The suture 34 may also be braided or may be ofother materials and have other configurations. The suture 34 in FIG. 1is shown extending from a catheter sheath introducer 44. The suture 34may also extend directly from an incision in a patient.

FIGS. 2-4 illustrate one embodiment of a knot placement device 100 thatmay be used to apply a knot to the suture 34. The knot placement device100 comprises a handle 102 and a shall 104 extending distally from thehandle. The handle 102 preferably comprises an elongate tubular bodyextending from a proximal end to a distal end, and comprises an actuator106 and a distal end portion 110. The handle 102 may further comprise acam 108 and a spring 112, shown in its rest position, disposed betweenthe cam 108 and end portion 110. The actuator 106 may be a thumb orfinger button in contact with the cam 108. End portion 110 may befixedly attached to an outer tube 114 by glue, press fit, injectionmolding, or other suitable means know to one of ordinary skill in theart. An intermediate tube 116 may be concentrically and slidablydisposed within the outer tube 114. A push rod 118 is concentrically andslidably disposed within the intermediate tube 116 and fixedly attachedto the cam 108. It should be appreciated that it is contemplated thatthe knot placement device 100 does not necessarily comprise anintermediate tube 116; however its inclusion provides certain benefits.

As shown in FIG. 4, depression of the actuator 106 causes the cam 108 tomove distally, compressing the spring 112 (not shown), thereby movingthe push rod 108. After traveling for a certain desired distance, thecam 108 engages a proximal end of the intermediate tube 116, causing theintermediate tube 116 to also move distally. Upon release of theactuator 106, the spring 112 expands to move the cam 108 and the pushrod 118 proximally. In the illustrated embodiment, the intermediate tube116 is freely slidable over the push rod 118.

In one embodiment, not shown, the cam 108 comprises a detent in thesurface which contacts the actuator 106. The detent may signal to theuser a specific degree of advancement of the push rod 118, theintermediate tube 116, or both. For example, the detent may signal thatthe push rod has been advanced sufficiently far to insert the plug intothe knot body, as described below. The detent may also indicate travelup until, but not including, the point at which the cam 108 engages theintermediate tube 116. The detent may be shaped so as to prevent theactuator 106 from returning to its original position. The cam maycomprise multiple detents to indicate multiple increments of travel. Toreturn the actuator to its initial position, the actuator and cam mayinclude a mechanism such that after the actuator is fully depressed, theactuator may automatically return to its initial position.Alternatively, the actuator may have a locked configuration, either atone of the detents or in a fully depressed configuration, and the handlemay include a mechanism by which a second actuator is used to releasethe cam and actuator to return to their initial positions. Furtherdetails of such mechanisms are found in application Ser. No. 11/235,751filed Sep. 27, 2005, the entirety of which is hereby incorporated byreference,

In one embodiment, not shown, the intermediate tube 116 may comprise akeyway and the outer tube 114, the end portion 110, or both may comprisea key. Alternatively, the intermediate tube 116 may comprise a key andthe outer tube 114, the end portion 110, or both may comprise a keyway.Providing such a key and keyway may be used to keep the intermediatetube 116 aligned with the outer tube. Other embodiments are contemplatedto maintain rotational alignment of the intermediate tube, such asrotationally fixing the intermediate tube relative to the push rod.Providing such a key and keyway may also be used to constrain the rangeof sliding movement of the intermediate tube 116.

As shown in FIG. 5, a knot, comprising a knot body 124 and a plug 126,is disposed within the outer tube 114 at its distal end. The knot body124 may be retained in the outer tube 114 by a net fit or press fit.Alternatively, the fit between the knot body 124 and the outer tube 114may not retain the knot body 124 in the outer tube 114. The knot body124 is preferably at the distal end of the outer tube 114, and mayprotrude slightly distal to the distal end of outer tube 114. The plug126 is positioned proximal to the knot body 124, and may be slidablydisposed within the intermediate tube 116, having a distal end locatedproximally from the knot body and distally from the push rod 118. Theplug 126 has an outer dimension configured to be inserted into an innercavity of the knot body 124. The intermediate tube 116 is preferablysized and positioned such that its distal end may abut knot body 124.

As shown in FIGS. 5, 6 and 8, the outer tube 114 may include a side hole120 near its distal end. As shown in FIGS. 5, 7, 9 a and 9 b, theintermediate tube 116 may include a slot 122 extending proximally fromits distal end, forming a C-shaped cross section. At a proximal end ofthe slot 122, a sharpened cutting surface 123 may be provided to cutsuture 34, as described below. The slot 122 is preferably rotationallyaligned with the opening 120, such as by using a key/keyway arrangementas described above. The slot 122 is also preferably axially aligned withthe opening 120, although it will be appreciated that because of theability of the intermediate tube 116 to slide relative to push rod 118,the intermediate tube may be positioned with the slot 122 proximal tothe opening 120 and its distal end proximal to the plug 126. The slot122 may also be spaced from the distal end of the intermediate tube,such that the distal end of the tube still forms a complete circle incross-section. The outer tube 114, intermediate tube 116 and push rod118 may be made of any suitable material, including but not limited tometals, plastics, and a combination of metals and plastics.

As shown in FIG. 5, in a preloaded configuration, the knot placementdevice 100 may include a threader 128 comprising a tab 132 and a loopedwire 130 passing through the side hole 120 in the outer tube 114. Thewire 130 preferably extends through the slot 122 located in theintermediate tube 116, and through knot body 124, exiting throughopening 136 at the distal end of the knot body 124. The threader 128 isused to load the suture into the knot placement device as describedbelow. The threader 128 also prevents the knot body 124 from escapingfrom the placement device 100 when the knot body is provided with anouter dimension of the same or smaller size than the inner wall of theouter tube 114.

With reference to FIGS. 5 and 10, the knot body 124 may be generallytubular and comprise a proximal end, a distal end, and a longitudinalaxis. The knot body 124 preferably further defines an inner cavity andcomprises an opening 136 at its distal end. The knot body may be of agenerally constant inner diameter and outer diameter. Alternatively, theinner diameter, the outer diameter, or both may generally taper alongthe longitudinal axis of the knot body. Alternatively, the innerdiameter, the outer diameter, or both may generally taper along aportion of the longitudinal axis and may be of a generally constantinner diameter, outer diameter or both over a portion of thelongitudinal axis.

The opening 136 at the distal end of the knot body may, in someembodiments, be of a reduced diameter relative to an inner cavity of theknot body 124. The knot body also comprises an opening 138 at theproximal end. The opening 138 at the proximal end may, in someembodiments, be of a reduced diameter relative to an inner cavity of theknot body 124. The knot body may further comprise protrusions 134extending from the inner surface of the knot body 124 toward thelongitudinal axis. Protrusions 134 may be formed as rings asillustrated, or as spirals, spikes, bumps, or other suitable structuresor combinations of structures.

Referring to FIGS. 5 and 10, in one embodiment, the knot body 124 may belocated distally from the plug 126 within the outer tithe 114. The plugis preferably sized to be inserted into the inner cavity of the knotbody 124, and may have a tapered configuration as shown in FIG. 10.Alternatively, the plug 126 may have a constant cross-section over amajority of its length, such as shown in FIG. 5, with a tapered,chamfered or rounded distal end for facilitating insertion into the knotbody 124. The outer dimension of the plug 126 may be slightly largerthan the inner dimension of the cavity of the knot body 124, such thatwhen the plug is inserted into the cavity, a relatively secure tit isprovided between the two. The protrusions 134 within the knot bodyfurther facilitate the relative securement. The plug 126 may alsocomprise indentations, not shown, for receiving the protrusions 134 tosecure the plug 126 more surely in the knot body 124. Other embodimentsare contemplated wherein protrusions are formed on the plug 126 with orwithout indentations formed in the inner cavity of the knot body 124. Itis also contemplated that in some embodiments both the plug 126 and theknot body 124 may comprise protrusions and indentations, respectively.In certain embodiments, insertion of the plug 126 into the knot body 124may cause the knot body 124 to slightly expand. Both the knot and theknot body may be formed of any suitable resilient materials, and in oneembodiment, are made from the same material as the suture, morepreferably polypropylene.

FIGS. 19-23 illustrate one embodiment for placing a knot utilizing theknot placement device 100 described above. With reference to FIG. 19, apair of sutures ends 40 and 42 may be passed through the loop 130 ofthreader 128. The threader is preloaded into the knot placement device100 as described above. The tab 132 of threader 128 may be pulledproximally to dispose suture 34 in the device, as shown in FIG. 20.Suture 34 may be held in tension, by hand or otherwise, while the device100 is advanced until the knot body 124 or shaft 104 contacts at leastone of tissue portions 36 and 38, as illustrated in FIG. 20. Theactuator 106 may be depressed to advance the push rod 118, therebyforcing the plug 126 distally into the knot body 124 and trapping suture34 there between the plug 126 and the knot body 124, as shown in FIG.21. The actuator may be further depressed until the cam 108 contacts theproximal end of intermediate tube 116, causing the intermediate tube 116to contact knot body 124 and eject the knot from the shaft 104. As shownin FIG. 22, advancement of intermediate tube 116 may also cause cuttingsurface 123 to sever suture 34 where it extends out of opening 120. Theknot placement device may then be removed, leaving the knot in placeagainst the tissue portions, as shown in FIG. 23.

In one embodiment, the knot may be ejected from the shaft 104 whileleaving the sutures 34 un-severed. For example, the knot may be ejectedbefore the cutting surface 123 reaches the suture 34. In anotherembodiment, no intermediate tube is provided, and the suture may be cutmanually.

In an embodiment including the intermediate tube, the device 100 may beconfigured such that the distal ends of the outer tube 114, intermediatetube 116, and the push rod 118 lie generally flush relative to oneanother and are held relatively in position. This position may be held,for example, by depressing the actuator until it rests in a detent incam 108. The detent may signal to the user that the plug 126 has beeninserted into knot body 124, but also that the sutures 34 have not beencut. At such time, the placement device may be used to further advancethe knot against tissue portions 36 and 38 using the distal end surfaceof the shaft. The actuator may be further depressed to advance the pushrod 118 and intermediate tube 116 to sever sutures 34.

The actuator 106 and cam 108 may also be provided with lockingmechanisms that prevent the actuator 106 from returning to its originalposition. Further details are provided in application Ser. No.11/235,751 filed Sep. 27, 2005, the entirety of which is herebyincorporated. by reference. Such an embodiment may be advantageous tohold the push rod flush with the distal end of the outer tube to providea surface that can be utilized to further advance and position the knotagainst tissue portions 36 and 38.

It will be appreciated that other embodiments are contemplated withoutuse of the intermediate tube, but are still capable of severing thesuture. For example, the push rod may be provided with portions ofdiffering diameter. A distal, smaller diameter may be sized to engagethe plug 126 to push the plug into the knot body 124. A proximal, largerdiameter may be provided on the push rod, which includes a sharpenedsurface at the transition between the larger and smaller diametersections. Once the smaller portion of the push rod pushes the plug 126into the knot body 124, the larger portion of the push rod may engagethe knot body 124 to push the knot out of the placement device, whilethe sharpened surface on the push rod may sever the suture.

In the embodiment described above, when the knot body 124 and the plug126 as described above are secured together, suture portions extendingthrough the inner cavity of the knot body from opening 136 to opening138 will be fixedly secured therein, forming a knot. It will beappreciated that many other embodiments are possible for forming a knot,including various other shapes and configurations for the knot body andplug, as well as embodiments wherein only one component may be used toprovide securement relative to a suture. It will also be appreciatedthat in those embodiments in which the knot comprises a knot body andplug, the plug may be located within the shaft proximally from the knotbody or the knot body may be located within the shaft proximally fromthe plug.

For example, in another embodiment of a knot, shown in FIG. 11, a plug146 is provided having a pair of holes 148 extending divergently fromone end of the plug (e.g., a proximal end) to the diametrically opposed,outer surfaces of the plug. A shoulder 149 of increased outer diametermay be located at one end of plug 146 (e.g., the proximal end). When theplug 146 is inserted into a hollow knot body, the plug 146 and knot body144 cooperate to secure the suture 34 therebetween.

In another embodiment, shown in FIG. 12, a plug 156 may comprise twosections having different outer diameters. A knot body 154 has anopening 136 with an inner surface 160. A surface 162 of plug 156 mayhave a smaller diameter than an interior surface 164 of knot body 154. Asurface 158 of plug 156 may have a diameter such that surface 158engages surface 160 of knot body 154 and cooperate to hold sutureportions securely therein.

In another embodiment, shown in FIGS. 13 and 14, a plug 176 comprises alongitudinally-extending slot 178 such that plug 176 is generallyfork-shaped. The slot 178 extends from the distal end partially to theproximal end. Suture 34 extends through the knot body 174, through theslot 178, and out from the plug 176, preferably on opposite sides of theplug 176. Insertion of the plug 176 into knot body 174 preferably causescompression of the slot to securely fix the suture portions within theslot. It will he appreciated that in this embodiment, the knot placementdevice can either be actuated to move the plug distally into the knotbody, or alternatively, may be actuated to move the knot body distallyover the plug.

In another embodiment, shown in FIG. 15, a pair of side holes 188 areprovided at spaced locations along the length of a plug 186. Sutureportions pass from an end hole at one end of the plug 186, outwardlythrough one of the side holes, and then inwardly back into the body ofthe plug and out an opposite end hole. When the knot body 184 is slidover the plug, either by being advanced distally over the plug or byhaving the plug advanced distally into the knot body, the suture 34 issecured relatively between the plug and the knot body.

In another embodiment, shown in FIGS. 16 a and 16 b, a knot body 194comprises two side holes 198. Suture 34 may be routed through knot body194 either from within the body, out through one of the side holes, andback into the body through the other side hole, as shown in FIG. 16 a,or may be routed into one of the side holes from outside the body, intothe body, and then out the other side hole, as shown in FIG, 16 b. Ineither embodiment, a plug 196 may then be used to secure the suturerelative to the knot body.

In another embodiment, shown in FIGS. 17 a and 17 b, a knot 200comprises a single component or knot body. A plate, ring or otherstructure, such as a flat resilient member, may be provided with twoholes 202. As shown in FIG. 17 b, the plate is bent to form a “U” shape,to allow the suture 34 to be passed therethrough. The plate may be madeof an elastic or shape memory material which springs back to itsflattened configuration, shown in FIG. 17 a, which locks the suture inplace relative to the plate. Other embodiments are also contemplated inwhich suture portions are provided through a tortuous path of a knotbody. A threader as described above may be used to guide the sutureportions through the knot body while it is positioned within a knotplacement device. Once ejected from the knot placement device, the knotbody may assume a different configuration which locks the suture inplace relative to the knot body.

In another embodiment, shown in FIGS. 18 a, 18 b, and 18 c, a knot 204comprises a tube having an upper wall 206 and a lower wall 208. Theupper wall comprises three linearly-spaced apertures 210. The lower wallcomprises two apertures 212 to create a displaceable section 214 in thelower wall 208. The displaceable section 208 is displaced toward thecenter of the knot 204 by any suitable means, such as a curved rod 216as illustrated in FIG. 18 b. A suture 34 is threaded in and out of theapertures 210 in the upper wall and around the displaceable section 214of the lower wall. As the knot 204 is ejected from the knot placementdevice, the displaceable section 214 is allowed to move toward itsoriginal position to more surely secure the suture 34 within the knot204 as illustrated in FIG. 18 c.

In another embodiment, shown in FIGS. 24 and 25, a knot comprises a knotbody 124 and a plug 126 such as described above, but with the knot bodyhaving an atraumatic tip 300. The tip 300 may be rounded and have anouter diameter about the same as that of the outer tube 114. As shownmore particularly in FIG. 25, the tip may have a flat transition 302 aswell. The tip 300 may be integrally formed with the knot body 124 or maybe separately attached. As illustrated, the tip 300 may have an aperture304 extending axially through the tip, opening to the cavity inside theknot body. When the knot is delivered into a patient as described above,the atraumatic tip prevents damage to the patient.

Various other embodiments are contemplated for the knot. For example, aknot may simply comprise a tube with a sufficiently small inner diameterthrough which suture portions may be positioned and held. In anotherembodiment not shown, the plug may comprise a shoulder located near itsproximal end having an increased outer diameter. The shoulder may not beinserted into the knot body, but may be used to push the knot out of theplacement device once the plug has been inserted into the knot body.

It should be understood that certain variations and modifications ofthis invention will suggest themselves to one of ordinary skill in theart. The scope of the present invention is not to be limited by theillustrations or the foregoing descriptions thereof.

1. A knot placement device comprising: an elongate shaft with proximaland distal ends and a lumen extending therethrough; a knot positioned inthe distal end of the elongate shaft within the lumen; a push rod havingproximal and distal ends slidably disposed in the lumen of said elongateshaft; and an actuator configured to distally advance said push rodrelative to said elongate shaft to distally engage the knot.
 2. Thedevice of claim 1, wherein depression of the actuator distally advancessaid push rod.
 3. The device of claim 1, wherein the actuator comprisesa locking mechanism configured to lock the position of the push rod. 4.The device of claim 1, further comprising an intermediate tube havingdistal and proximal ends concentrically and slidably disposed betweensaid shaft and said push rod, the proximal end of said intermediate tubeextending through the proximal end of said elongate shaft into saidhandle.
 5. The device of claim 4, wherein partial depression of theactuator distally advances said push rod and additional depression ofthe actuator distally advances said intermediate tube.
 6. The device ofclaim 4, wherein the distal end of the intermediate tube comprises acutting member.
 7. The device of claim 4, wherein said shaft comprises akeyway and wherein said intermediate tube comprises a key configured tobe inserted in said keyway.
 8. The device of claim 1, wherein the knotcomprises a knot body and a plug, the plug being positioned in the lumenof the shaft proximal of the knot body, wherein distal advancement ofthe push rod pushes the plug distally into the knot body and ejects theknot from the shaft.
 9. The device of claim I, wherein the knot isconfigured to receive at least one suture portion therein, and whereindistal advancement of the push rod secures the suture portion relativeto the knot and ejects the knot from the lumen of the shaft.
 10. Thedevice of claim 1, wherein the shaft further comprises a side holeproximal to the distal end.
 11. A knot placement device comprising: ahandle; an elongate shaft with proximal and distal ends and a lumenextending therethrough, the proximal end of said shaft coupled to saidhandle, the elongate shaft further comprising aside hole near its distalend; an intermediate tube, having proximal and distal ends and a lumenextending therethrough, slidably disposed in the lumen of said elongateshaft, the proximal end of said intermediate tube extending through theproximal end of said elongate shaft into said handle, the intermediatetube further comprising a cutting surface; a push rod having proximaland distal ends slidably disposed in the lumen of said intermediatetube, the proximal end of said push rod extending through the proximalend of said intermediate tube into said handle; an actuator located onsaid handle, said actuator configured to distally advance said push rodand said intermediate tube relative to said elongate shaft; and a knotcomprising a knot body and a plug positioned in the lumen of theelongate shaft at the distal end thereof; wherein at least one of theknot body and the plug is configured to receive at least one sutureportion extending into the lumen of the elongate shaft at the distalend, the at least one suture portion exiting the shaft through the sidehole; wherein distal advancement of the push rod moves the plugrelatively into the knot body to secure the at least one suture portion,and further distal advancement of the push rod causes the cuttingsurface of the intermediate tube to sever the at least one sutureportion and eject the knot from the lumen of the shaft.
 12. The knotplacement device of claim 11, wherein the plug is positioned proximallyof the knot body within the lumen of the shaft, such that distaladvancement of the push rod pushes the plug into the knot body.